Robot Lawn Mower Boundary-Wire Sensing for Accurate Distance Control
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Solution Overview
Problem
Conventional lawn mowers require manual operation, leading to labor costs and inconvenience, as modern individuals find it difficult to mow lawns efficiently, prompting the need for an automated solution that can accurately measure and maintain distance from boundary wires.
Innovation Solution
A lawn mower robot equipped with sensing units featuring multiple coils to detect voltage values induced by boundary wires, allowing the controller to determine and maintain the distance between the robot and the boundary wire, ensuring accurate navigation within a defined work area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual lawn mowing is used, then labor costs are generated and operation becomes inconvenient, but automated robot mowing requires complex sensing and control systems to accurately measure distance from boundary wires
Solution Approach 1:
The sensing unit is divided into multiple independent coils (first coil, second coil, third coil) with different orientations. Each coil senses voltage in a specific direction, and the controller processes these separate signals to calculate distance. This segmentation allows the system to achieve accurate 3D distance measurement while keeping each individual coil simple and manageable.
Solution Approach 2:
The patent uses voltage induction as an intermediary mechanism between the boundary wire and the robot. The boundary wire generates a magnetic field that induces voltage in the sensing coils, and this voltage signal serves as the mediator that the controller processes to determine distance. This intermediary approach enables non-contact, accurate distance measurement without requiring complex direct sensing hardware.
2Measurement precision
If multiple coils are used to sense voltage values in different directions, then distance measurement accuracy improves, but the device complexity and installation complexity increase
Solution Approach 1:
Each coil is assigned a specific sensing direction (forward, sideways, upward) with distinct local quality. The first coil senses in the forward direction, the second in the sideways direction, and the third in the upward direction. This local quality differentiation allows the system to achieve comprehensive 3D distance measurement by combining signals from coils with specialized, simplified individual functions.
3Extent of automation
If the boundary wire is installed to form a closed loop for accurate distance determination, then the robot can operate autonomously within the work area, but the installation process becomes more complex
Solution Approach 1:
The robot uses the voltage signals from the boundary wire to automatically determine its position and distance without requiring external guidance or manual intervention. The system self-calibrates by processing the voltage values from multiple coils to calculate distance, enabling autonomous operation. This self-service capability achieves high automation while keeping the boundary wire installation relatively simple, as the wire only needs to form a closed loop without requiring precise positioning or complex configuration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The robot accurately acquires distance information and maintains a stable trajectory along the boundary wire, reducing labor costs and improving installation convenience by enabling autonomous operation within a closed loop formed by the boundary wire.
Implementation Method 1
sensing units sensing voltage values induced by the boundary wire
Data Source
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AI summary
Disclosed are a lawn mower robot and a control method thereof. The lawn mower robot being operated in a work area defined by a boundary indication unit including a boundary wire; and comprising: a main body configured to move within the work area defined by the boundary wire, wherein the main body includes: sensing units configured to sense voltage values induced by the boundary wire; and a controller configured to determine a distance between the main body and the boundary wire from the voltage values sensed by the sensing units, wherein: each sensing unit includes at least two coils differently installed; the two coils are respectively configured to sense voltage values within the same area defined by the boundary wire; and wherein the controller is configured to determine the distance by summing the voltage values sensed by the two coils.